U.S. patent number 6,609,484 [Application Number 10/013,578] was granted by the patent office on 2003-08-26 for engine cooling system.
This patent grant is currently assigned to Caterpillar Inc. Invention is credited to David R. Berta, Aubery W. Penn, Terry L. Schaffer.
United States Patent |
6,609,484 |
Penn , et al. |
August 26, 2003 |
Engine cooling system
Abstract
An engine cooling system for a work machine or the like having
an engine with a turbocharger and an aftercooler. A separate
circuit aftercooler cooling circuit is provided. A radiator
assembly includes a first group of radiator cores and a second
group of radiator cores. Some coolant cooled in the first group of
radiator cores is passed from the radiator assembly to an engine
cooling circuit. Another portion of coolant cooled in the first
group of radiator cores is passed to the second group of radiator
cores, for additional cooling thereof. From the second group of
radiator cores, coolant is passed to the separate circuit
aftercooler cooling circuit.
Inventors: |
Penn; Aubery W. (Washington,
IL), Berta; David R. (Varna, IL), Schaffer; Terry L.
(Peoria, IL) |
Assignee: |
Caterpillar Inc (Peoria,
IL)
|
Family
ID: |
21760658 |
Appl.
No.: |
10/013,578 |
Filed: |
December 11, 2001 |
Current U.S.
Class: |
123/41.29;
123/41.31; 165/51 |
Current CPC
Class: |
F28D
1/0417 (20130101); F01P 7/165 (20130101); F01P
3/18 (20130101); F02B 29/0443 (20130101); Y02T
10/146 (20130101); F01P 2060/04 (20130101); F01P
11/029 (20130101); F01P 2003/187 (20130101); F01P
2060/02 (20130101); Y02T 10/12 (20130101); F01P
2003/185 (20130101); F01P 2003/182 (20130101) |
Current International
Class: |
F01P
3/18 (20060101); F02B 29/04 (20060101); F01P
7/16 (20060101); F02B 29/00 (20060101); F01P
7/14 (20060101); F01P 3/00 (20060101); F28D
1/04 (20060101); F01P 11/02 (20060101); F01P
11/00 (20060101); F01P 003/00 () |
Field of
Search: |
;123/41.29,41.31 ;165/51
;60/599 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kamen; Noah P.
Attorney, Agent or Firm: Taylor; Todd T
Claims
What is claimed is:
1. An internal combustion engine, comprising: a block defining a
coolant channel and including a coolant channel inlet and a coolant
channel outlet, said coolant channel inlet being an entrance to
said coolant channel and said coolant channel outlet being an exit
from said coolant channel; a radiator assembly including first and
second groups of radiator cores, first and second radiator inlets
and first and second radiator outlets, said first radiator inlet
coupled to said coolant channel outlet and said first radiator
outlet coupled to said coolant channel inlet, said first radiator
outlet associated with said first group of radiator cores and said
second radiator outlet associated with said second group of
radiator cores, said second group of radiator cores coupled to
receive a coolant flow from said first group of radiator cores; a
separate circuit aftercooler pump including a pump inlet and a pump
outlet, said pump inlet coupled to said second radiator outlet; and
an aftercooler including an aftercooler coolant inlet and an
aftercooler coolant outlet, said aftercooler coolant inlet coupled
to said pump outlet and said aftercooler coolant outlet coupled to
said second radiator inlet.
2. The internal combustion engine of claim 1, including a radiator
bottom tank having an inlet compartment coupled to said first and
second radiator inlets, a first outlet compartment coupled to said
first radiator outlet and a second outlet compartment coupled to
said second radiator outlet.
3. The internal combustion engine of claim 2, said tank having a
baffle separating said inlet compartment into first and second
sections, with restricted flow therebetween, said first radiator
inlet coupled to said first section and said second radiator inlet
coupled to said second section.
4. The internal combustion engine of claim 2, said first group of
cores fluidly coupled between said inlet compartment and said first
outlet compartment.
5. The internal combustion engine of claim 2, said tank having an
intermediate compartment coupled to said first outlet compartment,
said second group of cores coupled in flow communication between
said intermediate compartment and said second outlet
compartment.
6. The internal combustion engine of claim 5, said first group of
cores fluidly coupled between said inlet compartment and said first
outlet compartment.
7. A cooling system for an internal combustion engine, comprising:
a radiator assembly including a first group of radiator cores and a
second group of radiator cores, at least one radiator inlet and
first and second radiator outlets, said first radiator outlet
associated with said first group of radiator cores and said second
radiator outlet associated with said second group of radiator
cores, said second group of radiator cores coupled to receive a
coolant flow from said first group of radiator cores; a separate
circuit aftercooler pump including a pump inlet and a pump outlet,
said pump inlet coupled to said second radiator outlet; and an
aftercooler including an aftercooler coolant inlet and an
aftercooler coolant outlet, said aftercooler coolant outlet coupled
to said at least one radiator inlet.
8. The cooling system of claim 7, including a radiator tank having
an inlet compartment coupled with said at least one radiator inlet,
a first radiator outlet compartment coupled to said first radiator
outlet and a second outlet compartment coupled to said second
radiator outlet.
9. The cooling system of claim 7, said tank having an intermediate
compartment in fluid flow communication between said first outlet
compartment and said second group of radiator cores.
10. The cooling system of claim 8, said first group of radiator
cores in flow communication between said inlet compartment and said
first outlet compartment.
11. The cooling system of claim 8, said tank having a baffle
separating said inlet compartment into first and second sections,
with restricted flow therebetween.
12. The cooling system of claim 10, said at least one radiator
inlet including a first inlet coupled with said first section of
said inlet compartment and a second inlet coupled with said second
section of said inlet compartment, and said aftercooler coolant
outlet coupled to said second radiator inlet.
13. A method of cooling an internal combustion engine, comprising
the steps of: providing an engine cooling circuit, a radiator
assembly having first and second groups of radiator cores, an
aftercooler, a separate circuit aftercooler cooling circuit, and a
heat transfer fluid; cooling said fluid in said radiator assembly;
flowing a portion of said fluid from said first group of radiator
cores to the engine cooling circuit and back to the radiator
assembly; and flowing another portion of said fluid from said first
group of radiator cores to said second group of radiator cores,
through said aftercooler, and back to said first group of radiator
cores.
14. The method of cooling of claim 13, including the step of
providing a separate circuit aftercooler pump; and flowing fluid
from said radiator assembly to said aftercooler and from said
aftercooler to said radiator assembly using said pump.
15. The method of cooling of claim 13, including the step of
flowing said another portion of said fluid from said first group of
radiator cores to said second group of radiator cores.
16. The method of cooling of claim 13, including the steps of:
providing a dual pass radiator assembly having an inlet compartment
and first and second outlet compartments; flowing said fluid from
the inlet compartment through said first group of radiator cores
and into said first outlet compartment; and flowing said another
portion of said fluid from said first outlet compartment through
said second group of radiator cores and to said second outlet
compartment.
17. The method of cooling of claim 16, including the step of
providing a separate circuit aftercooler pump and flowing fluid
from said radiator assembly to said aftercooler and from said
aftercooler to said radiator assembly using said pump.
18. The method of cooling of claim 13, including the step of
operably coupling a shunt tank assembly with said radiator assembly
and said aftercooler.
Description
ENGINE COOLING SYSTEM
1. Technical Field
The present invention relates generally to cooling systems for
internal combustion engines, and, more particularly, to cooling
systems for internal combustion engines also having turbochargers
with aftercoolers.
2. Background
Internal combustion engines used to operate heavy mechanical
equipment, such as large tractors, generate considerable heat that
must be dissipated. If not properly dissipated, heat reduces
operating efficiency of the engine, and can ultimately lead to
damage of the engine.
It is known to provide engine cooling systems which flow a coolant
through the block of the engine to cool the engine. The coolant
captures heat from the engine and releases the heat through a
radiator in which the coolant passes in heat exchange relationship
with air. The radiator includes a series of tubes through which the
coolant is pumped, and airflow induced by a fan cools the tubes,
and hence the coolant flowing through the tubes. The coolant is
pumped through various engine components, such as the engine block,
an engine oil cooler or the like, to capture heat from the
components.
In the operation of an internal combustion engine, the amount of
combustion air that can be delivered to the intake manifold of the
engine, for combustion in the engine cylinders, is a limiting
factor in the performance of the engine. Atmospheric pressure is
often inadequate to supply the required amount of air for proper
and efficient operation of an engine.
It is known to use one or more turbochargers for compressing air to
be supplied to one or more combustion chambers within corresponding
combustion cylinders. The turbocharger supplies combustion air at a
higher pressure and higher density than existing atmospheric
pressure and ambient density. The use of a turbocharger can
compensate for lack of power due to altitude, or to increase the
power that can be obtained from an engine of a given displacement,
thereby reducing the cost, weight and size of an engine required
for a given power output. The turbocharger typically includes a
turbine driven by exhaust gases from the engine, and one or more
compressors driven by the turbine through a turbocharger shaft
common to both the turbine and the compressor or compressors. A
stream of exhaust gases from the engine is conducted from the
exhaust manifold to the turbine, and the exhaust gas stream passing
through the turbine causes a turbine wheel to rotate. Rotation of
the turbine wheel rotates the common shaft interconnecting the
turbine wheel and one or more compressor wheels in the compressor
section, thereby rotating the compressor wheels. Air to be
compressed is received in the compressor section, wherein the air
is compressed and supplied to the intake air system of the
engine.
It is known to condition the boost air flowing from the compressor
or compressors to affect the overall turbocharger performance
and/or the engine efficiency. In turbochargers having multiple
stage compressors, compressing the air in the first compressor
significantly raises the temperature of the air, increasing the
power required by the second compressor to achieve a desired
pressure boost. To overcome the detrimental effects of the increase
in temperature, so called "intercoolers" have been provided in the
flow path between the first compressor outlet and the second
compressor inlet. Similarly, so called "aftercoolers" have been
used after the turbocharger in turbochargers having both single
stage and multi-stage compressors. The aftercooler cools the
compressed air being supplied to the intake manifold, thereby
increasing the oxygen content per unit volume, to better support
combustion in the cylinders and decrease engine operating
temperatures.
It is known to supply coolant from the engine cooling system to
circulate through the aftercooler, providing a heat exchange medium
for the compressed air also flowing through the aftercooler. Heat
from the compressed air stream is captured by the coolant and
released in the readiator. Reducing the temperature of the charge
air can reduce engine emissions and increase engine efficiency.
In an aftercooler system, it is known to provide a separate coolant
circuit from the radiator to the aftercooler, including a separate
circuit aftercooler (SCAC) pump for circulating the coolant to the
aftercooler. However, the cooling efficiency of such systems have
not always met expectations under all operating conditions.
A turbocharged engine cooling system using a two-pass radiator and
a separate circuit aftercooler pump in an aftercooler cooling
circuit is shown in U.S. Pat. No. 6,158,399.
In view of the engine efficiency and emissions reduction benefits
obtained from adequate aftercooling of the combustion air, it is
desirable to have an improved cooling system that provides adequate
aftercooler cooling under various operating conditions.
The present invention is directed to overcoming one or more of the
problems as set forth above.
SUMMARY OF THE INVENTION
In one aspect thereof, the present invention provides an internal
combustion engine with a block defining a coolant channel,
including a coolant channel inlet and a coolant channel outlet. A
radiator assembly includes first and second groups of radiator
cores, first and second radiator inlets and first and second
radiator outlets. The first radiator inlet is coupled to the
coolant channel outlet and the first radiator outlet is coupled to
the coolant channel inlet. The first radiator outlet is associated
with the first group of radiator cores, and the second radiator
outlet is associated with the second group of radiator cores. A
separate circuit aftercooler pump includes a pump inlet and a pump
outlet. The pump inlet is coupled to the second radiator outlet. An
aftercooler includes an aftercooler coolant inlet and an
aftercooler coolant outlet. The aftercooler coolant inlet is
coupled to the pump outlet and the aftercooler coolant outlet is
coupled to the second radiator inlet.
In another aspect thereof, the present invention provides a cooling
system for an internal combustion engine, with a radiator assembly
including a first group of radiator cores and a second group of
radiator cores, at least one radiator inlet and first and second
radiator outlets. The first radiator outlet is associated with the
first group of radiator cores, and the second radiator outlet is
associated with the second group of radiator cores. A pump includes
a pump inlet and a pump outlet. The pump inlet is coupled to the
second radiator outlet. An aftercooler includes an aftercooler
coolant inlet and an aftercooler coolant outlet, the aftercooler
coolant outlet being coupled to the at least one radiator
inlet.
In yet another aspect thereof, the present invention provides a
method of cooling an internal combustion engine, having steps of
providing an engine cooling circuit, a radiator having first and
second groups of radiator cores, an aftercooler, a separate circuit
aftercooler cooling circuit, and a heat transfer fluid; cooling the
fluid in the radiator; flowing a portion of the fluid from the
first group of radiator cores to the engine cooling circuit and
back to the radiator; and flowing another portion of the fluid from
the second group of radiator cores through the aftercooler and back
to the radiator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a preferred embodiment of the
engine cooling system of the present invention;
FIG. 2 is a top plan view of the radiator bottom tank shown in FIG.
1; and
FIG. 3 is a side elevational, schematic illustration of the
radiator shown in FIG. 2, illustrating the coolant flow through the
radiator.
DETAILED DESCRIPTION
Referring now more specifically to FIG. 1, an internal combustion
engine cooling system 10 is shown, for and as part of an engine 12.
Cooling system 10 includes an engine cooling circuit 14 and a
separate circuit aftercooler (SCAC) cooling circuit 16. Common to
engine cooling circuit 14 and SCAC cooling circuit 16 is a radiator
assembly 18.
Engine 12 includes an engine block 20 having one or more coolant
channels 22 provided therein, with a coolant channel inlet 24 and
one or more coolant channel outlets 26. Block 20 further defines
one or more combustion cylinders (not shown) in which fuel and air
are combusted in a known manner, and engine 12 includes pistons,
valves, manifolds and the like (not shown), descriptions of which
are not necessary to an understanding of the present invention.
Engine cooling circuit 14 includes a jacket water pump 28, an
engine oil cooler 30, transmission oil cooler 31, as well as
various coolant conduits 32 and valves and sensors (not shown) well
known to those skilled in the art.
SCAC cooling circuit 16 includes a SCAC pump 34 having an inlet 36
and an outlet 38. Various coolant conduits 32 are provided in SCAC
cooling circuit 16, interconnecting the various components of SCAC
cooling circuit 16. SCAC pump inlet 36 is connected in fluid flow
communication to radiator assembly 18, as will be described in
greater detail hereinafter, and SCAC pump outlet 38 is connected in
fluid flow communication to an aftercooler 40. Aftercooler 40
includes a coolant inlet 42 and a coolant outlet 44. Coolant inlet
42 is connected in fluid flow communication to SCAC pump outlet 38,
and coolant outlet 44 is connected in fluid flow communication to
radiator assembly 18, as will be described in greater detail
hereinafter. In aftercooler 40, coolant supplied thereto passes in
heat exchange relationship with combustion air from a turbocharger
46 operated by combustion gases from engine 12. Aftercooler 40
includes a charge air inlet 48 and a charge air outlet 50. Charge
air inlet 48 receives charge air from turbocharger 46 via a charge
air conduit (not shown) and charge air outlet 50 is connected in
flow communication to an intake manifold (not shown) of engine 12.
Turbocharger 46 may be a single or multiple stage turbocharger, in
any known manner or configuration, and a further.description
thereof is not necessary for an understanding of the present
invention. Further, aftercooler 40 can be of any of various
designs, and the details thereof are not necessary to an
understanding of the present invention.
It will be understood by those skilled in the art that engine 12
includes numerous other engine systems, controls and the like, not
shown in FIG. 1, which is merely a schematic illustration of the
cooling circuitry of engine 12 necessary for understanding the
present invention.
Radiator assembly 18 includes a plurality of radiator cores 60
which are divided into a first group 62 of radiator cores 60 and a
second group 64 of radiator cores 60. A bottom tank 66 is provided
for channeling and directing coolant flow from and to engine
cooling circuit 14, SCAC cooling circuit 16 and radiator cores 60.
Radiator cores 60 include coolant tubes 68, and may be provided as
a dual pass radiator, in which coolant flows upwardly in a first
tube 68 and downwardly in a second tube 68 from and to bottom tank
66. The tubes 68 of each core 60 in a dual pass configuration may
be provided in a front and back relationship relative to the
direction of airflow through the radiator. Coolant flows from
bottom tank 66 upwardly through a back tube 68 and downwardly
through a front tube 68 back into tank 66. The general pattern of
coolant circulation through a dual pass radiator is shown
schematically in FIG. 3. Air flows past and around tubes 68 in
radiator cores 60 to effect heat transfer therebetween. Airflow may
be induced by the operation of a fan (not shown).
As shown more clearly in FIG. 2, bottom tank 66 is divided into a
plurality of compartments, including an inlet compartment 70, a
first outlet compartment 72 and a second outlet compartment 74.
First group 62 of radiator cores 60 receives coolant flow from
inlet compartment 70 and provides coolant flow to first outlet
compartment 72. Thus, first group 62 of cores 60 is in fluid flow
communication between inlet compartment 70 and first outlet
compartment 72. An intermediate compartment 76 is connected to
first outlet compartment 72 by an internal channel or duct 78, to
receive coolant flow from first outlet compartment 72. Second group
64 of radiator cores 60 is connected in flow communication between
intermediate compartment 76 and second outlet compartment 74, and
thereby receives coolant flow from intermediate compartment 76 and
provides coolant flow to second outlet compartment 74.
Radiator assembly 18 further includes first and second radiator
inlets 80 and 82, each connected in flow communication to inlet
compartment 70.
First radiator inlet 80 receives coolant flow from engine 12 and
second radiator inlet 82 receives coolant flow from aftercooler 40.
Inlet compartment 70 may be provided with a baffle 74, separating
inlet compartment 70 into an inlet compartment first section 86 and
an inlet compartment second section 88. Baffle 84 is provided with
an opening 90, providing controlled, limited flow between section
86 and section 88. First inlet section 86 is connected to first
radiator inlet 80 and second inlet section 88 is connected to
second radiator inlet 82.
Radiator assembly 18 includes a first radiator outlet 92 connected
in flow communication between first outlet compartment 72 and
engine cooling circuit 14, and a second radiator outlet 94
connected in flow communication between second outlet compartment
74 and SCAC cooling circuit 16.
In the configuration of radiator assembly 18 shown, inlet
compartment 70 and intermediate compartment 76 are provided as back
compartments behind first and second outlet compartments 72 and 74,
which are front compartments relative to the direction of air flow
through radiator assembly 18. First and second radiator inlets 80
and 82 approach bottom tank 66 from the front thereof, and extend
through first outlet compartment 72 and an internal wall 96 of tank
66, to discharge directly into inlet compartment 70 and, more
specifically, into first and second sections 86 and 88 thereof,
respectively. However, it should be understood that the approach of
inlets 80 and 82 to bottom tank 66 can be different from that
shown, such as from the back thereof directly into inlet
compartment 70, without departing from the scope of the present
invention.
A shunt tank assembly 98 is provided, connected in known manner to
radiator assembly 18, engine cooling circuit 14 and SCAC cooling
circuit 16, to provide a reservoir of and overflow compartment for
heat transfer fluid or coolant 100 circulated through out engine
cooling system 10.
INDUSTRIAL APPLICABILITY
During use of engine cooling system 10, engine 12 is operated in
known manner, with the resultant and unavoidable generation of
heat. Engine 12 further operates turbocharger 46, to compress
charge air which is then passed through aftercooler 40, for cooling
thereof Radiator assembly 18 provides coolant to both engine
cooling circuit 14 and SCAC cooling circuit 16, to cool engine 12,
as well as the charge air passing through aftercooler 40.
Coolant from inlet compartment 70 of bottom tank 66 flows upwardly
through first group 62 of radiator cores 60, and then downwardly
therein, into first outlet compartment 72. A portion of the coolant
from first outlet compartment 72 is provided to engine cooling
circuit 14, in known manner. Another portion of coolant from first
outlet compartment 72 flows through internal channel or duct 78 to
intermediate compartment 76. From intermediate compartment 76,
coolant flows upwardly through second group 64 of radiator cores
60, and then downwardly therein into second outlet compartment 74.
From second outlet compartment 74, coolant is supplied via SCAC
pump 34 to aftercooler 40.
Coolant returning from engine cooling circuit 14 flows through
first radiator inlet 82 into inlet compartment 70, and specifically
into first section 86 of inlet compartment 70. Coolant returning
from SCAC cooling circuit 16 flows through second radiator inlet 82
into inlet compartment 70, and specifically into second section 88
of inlet compartment 70.
The present invention provides improved cooling for a separate
circuit aftercooler cooling circuit, in that a section of radiator
cores is provided dedicated to cooling coolant to be supplied to
the separate circuit aftercooler cooling circuit. Further, coolant
supplied to the separate circuit aftercooler cooling circuit is
provided with additional cooling, the coolant first having passed
through a first group of radiator cores and thereafter passing
through the second set of dedicated radiator cores for the separate
circuit aftercooler cooling circuit.
Other aspects, objects and advantages of this invention can be
obtained from a study of the drawings, the disclosure and the
appended claims.
* * * * *